Make IndexTester available (again)

The v0.13.0 release hid the IndexTester class in a test file but it's used elsewhere so put it back where it was.

Make AccessTestSuite visible again

In the last release the file containing AcessTestSuite was renamed which made it invisible outside of the repository. Turns out it's used elsewhere so rename it back.

Add Pointer mechanism

• Add Pointer mechanism developed initially in go-serial
  • mdbson/pointer.go
  • mdbson/pointer_test.go
  • mdbson/pointer_db_test.go
• Add AccessTestSuite.ConnectCollection() and ConnectTypedCollectionHelper() and refactor test suites to use them
• Move IndexTester into index_db_test.go and remove index_tester.go
• Various minor tweaks

Update dependencies

Avoiding vulnerable dependencies found with new GoLand analysis tool.

Updated testing and usage of Identity

• add unit tests for identity.go
• comment Identity struct to require bson:"inline" to work properly
• add Identity.ID() testing to typed collection unit tests

Move packed struct out of wrappers

Move type/raw packed struct out of the JSON and YAML wrappers:

• streamlines the wrapper objects
• makes the clear functionality unnecessary

Use $setOnInsert in FindOrCreate()

This is simpler than what I had been doing and should be more atomic.

Make CollectionDefinition fields visible

v0.10.1

Rename CollectionDefinition fields to be visible to other packages

Much change

Lots of work done including removal of CollectionCache unless and until I know what it should really do.

Generics version

Added generics and somewhat normalized various functionality and unit tests.